Carboxylesterase (CES) 2, an important metabolic enzyme, plays a critical role in drug biotransformation and lipid metabolism. Although CES2 is very important, few animal models have been generated to study its properties and functions. Rat Ces2 is similar to human CES2A-CES3A-CES4A gene cluster, with highly similar gene structure, function, and substrate. In this report, CRISPR-associated protein-9 (CRISPR/Cas9) technology was first used to knock out rat Ces2a, which is a main subtype of Ces2 mostly distributed in the liver and intestine. This model showed the absence of CES2A protein expression in the liver. Further pharmacokinetic studies of diltiazem, a typical substrate of CES2A, confirmed the loss of function of CES2A both in vivo and in vitro. At the same time, the expression of CES2C and CES2J protein in the liver decreased significantly. The body and liver weight of Ces2a knockout rats also increased, but the food intake did not change. Moreover, the deficiency of Ces2a led to obesity, insulin resistance, and liver fat accumulation, which are consistent with the symptoms of nonalcoholic fatty liver disease (NAFLD). Therefore, this rat model is not only a powerful tool to study drug metabolism mediated by CES2 but also a good disease model to study NAFLD.

中文翻译：

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羧酸酯酶2a基因CRISPR/Cas9敲除大鼠模型的构建与表征

羧酸酯酶 (CES) 2 是一种重要的代谢酶，在药物生物转化和脂质代谢中起着关键作用。尽管 CES2 非常重要，但很少有动物模型用于研究其特性和功能。大鼠Ces2与人CES2A - CES3A - CES4A基因簇相似，基因结构、功能、底物高度相似。在本报告中，CRISPR相关蛋白9（CRISPR / Cas9）技术最早用来敲除鼠Ces2a，这是一个主要的亚型CES2主要分布于肝脏和肠道。该模型显示肝脏中不存在 CES2A 蛋白表达。CES2A 的典型底物地尔硫卓的进一步药代动力学研究证实了 CES2A 在体内和体外的功能丧失。同时，肝脏中CES2C和CES2J蛋白的表达显着降低。Ces2a敲除大鼠的体重和肝脏重量也有所增加，但摄食量没有变化。此外，Ces2a的缺乏导致肥胖、胰岛素抵抗和肝脏脂肪堆积，这些都与非酒精性脂肪肝 (NAFLD) 的症状一致。因此，该大鼠模型不仅是研究CES2介导的药物代谢的有力工具，也是研究NAFLD的良好疾病模型。